The present invention relates to an improvement in the manner in which a diesel engine is brought to operating temperature during start up and cold weather operations. More specifically, to an add on unit that will use the heat naturally generated by the engine's exhaust system to speed up the warming of the engine. The present invention greatly reduces warm up time for diesel engines thereby minimizing the excessive wear and tear caused to such engines in cold weather and startup periods.
For a variety of reasons a typical truck diesel engine may spend between 40 and 70 percent of its useful life idling at low revolutions per minute (RPM)s. During this idling time, these engines consume from 1.5 to 3 gallons of diesel fuel per hour. From these facts it can be seen that in fuel costs alone this idling time adds significantly to the annual costs of operating a diesel truck and thus, anything that can be done to increase fuel efficiency during these periods could translate into large fuel savings.
It had long been thought by truck operators that the idling of diesel engines for long periods of time, such as overnight, had no adverse wear effects on the engine itself. This, however, is not the case. In fact, it has been estimated that one hour of idling time causes the equivalent wear to a diesel engine as 80 miles of driving.
For a diesel engine to operate efficiently it must maintain an internal temperature of 175 degrees Fahrenheit. If the temperature falls below this point it allows for the accumulation of water and sulfur in the engine. When a diesel engine is left to idle in cold weather the operating temperature often drops below the optimal operating temperature, thus, resulting in the above described situation. This condition dilutes the engine oil, which increases engine wear due to the lack of lubrication, and can cause the engine valves to stick which result in higher maintenance costs during the life of the engine.
Therefore, from the foregoing discussion it can be seen that it would be highly desirable to provide a method of maintaining a truck's diesel engine at a suitable temperature during periods of idle and in cold weather This method should accelerate the process of bringing an engine up to a proper operating temperature so as to optimize efficiency during startup and periods of idle.